Hello,
I really like the idea of the stone path adding a runspeed modifier. However, I'm not a huge fan of its appearance in mid-late game builds. I'd like to suggest adding a speed modifier to more blocks- specifically the craft-able stone and brick blocks. They are also more [street] road-like than the path blocks. As such, I think 1.4-1.5x speed would be perfect for the standard block/slabs. It would allow for more aesthetic flexibility within our builds while maintaining survival usability.